Mounting for crystal detectors



Feb. 21, 1928.

H. J. GUTH MOUNTING FOR CRYSTAL DETECTORS I Filed March 5. 1926 INVENTOR. fiW/W J 62 AT ORNEY.

' slot 21.

Patented Feb. 21, 1928.

* i UNITED" STATES -HENRY: J. GUTH,'OF GOLDEN, COLORADO.

MOUNTING FOR CRYSTAL DETECTORS.

Application filed March 5,1926. Serial no. 92,411. i 3

This invention relates to a mounting for the crystal detector unit in radio receiving sets, and has for its principal object the provision of a device of thischaracter which will give an unusually delicate, uniform contact pressure upon the crystal.

Another object of the invention is to provide means for supporting the Cat whisker so ,that it can have a universal movement over the face of the crystal.

A further object is to provide-means whereby the crystal may be readily removed from its cup. I

A still further object resides in the novel means for attaching the cat whisker to its supporting bar, whereby the use of set screws, solder and like is eliminated.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy,

and efficiency. These will become more apparent from the following description.

In the following detailed description of the invention, reference is had to the accoman in drawin which forms a art here p y b 9 of. Like numerals refer to like parts in all views of the drawing and throughout the description; 4

In the drawing:

Fig. 1 is an elevation of the novel detector unit in place on an instrument panel.

Fig. 2 is a plan view of the same.

Fig. 3 is a detail vertical section through the crystal cup, taken on the line 22, Fig. 1.

Fig. 1 is a detail View of the adjustment bar illustrating the method of attaching the cat whisker thereto. a

On the drawing, a section of the instrument panel of a radio set is illustrated at 10, upon which, the novel detector unit is mounted, The unit comprises a crystal cup 11, supported on a bolt 12 which passes through, and is locked to, the instrument panel 10 by means of nuts 13 and 14. Se-

cured in the crystal cup, by means of the usual set screws 15, is a crystal 16, upon which a cat whisker 17 bears.

The position of the cat whisker 17 upon the crystal is adjusted by an adjusting bar 18, terminating in an insulated finger grip 19. The adjusting bar is flattened along its mid-portion, as shown at 20, the flattened portion being provided with a longitudinal The adjusting bar 18 rests upon a stud 22 carrying a pin 23 arranged to pass tion.

gravity, there being no springs or clamps employed. By this arrangement, a very uniform and very delicate contact can be made between the crystal and the cat whisker, and, since the sensibility of a crystal detector depends upon the delicacy of this contact, the advantages of the mounting will be at once apparent. The cat whisker can be easily placed upon any part of the crystal, since it is free to swing about the pin 23 and also free to move across the stud 22. It is very desirable that the cat whisker extend vertically from the surface .of the crystal and not at an angle thereto. In the present device, this is accomplished by the flattened portion 20 of the adjusting bar. The cat whisker extends vertically to the surface of the flattened portion'20 and, since this surface always lies parallel to the horizontal axis of the stud 22, the cat whisker will always be maintained in a vertical posi- For attaching the-cat whisker to the adjusting bar, a hole 26 is provided through.

into the slots 2'7 until it becomes wedged therein, thus forming a perfect electrical and mechanical contact.

It is often very difficult to remove a mounted crystal from its crystallcup, it being necessary at times to invert the entire receiving set in order that the crystal will drop from its cup. To obviate this, I place a raised bottom 28 in the crystal cup and an opening 29 in its side. This construction allowsthe crystal to be readily lifted from its cup by means of a common pin 30, which is inserted in the opening 29 so as to exert an upward prying action upon the crystal,

as illustrated in Fig. 3.

While a specific form of the improvement has been described and illustrated herein, it is. desired to be understood that the same may be varied, within the scope of the appended claim Without departing from the an arm arranged to rest on said bar and-be 10 spirit of theinvention. I maintained by gravity alone, said arm hav- Having thus described the invention, What ing a longitudinal slot for the reception of V I claim and desire secured by Letters said pin; and a cat Whisker extending from 5 Patent is I said arm and adapted to rest on said crystal A crystal detector comprising a crystal so as to support one extremity of said bar; cup adapted to support a crystal; a hori- In testimony whereof, I ailix my sigzontal bar adjacent said crystal cup; a ver: nature.

tical pin projecting upwardly from saidbar; HENRY J. 

